Setup integration tests for the api

[elhmn]

Add integration tests for the api and Github Action workflow that will run this integration tests on commit push.

The integration tests should spin up using docker-compose an api and a postgres container that will be populated with some fixtures data, then used to run the integration tests. To run integration tests we can use postman collection with the newman cli, or use a different option that propose a more readable and reviewable test description config format.